WASHINGTON — While President Donald Trump has notoriously clashed with his predecessors since taking office, Vice President Mike Pence has been quietly cultivating his.

Pence speaks with Joe Biden on the phone at least once a month, and he’s had numerous conversations with Dick Cheney, even meeting in his West Wing office, according to people close to the two former vice presidents. Their discussions involve an exchange of ideas and advice, these people said, with Biden and Cheney offering their counsel on foreign and domestic policy issues, the interplay between the White House and Capitol Hill, and how to navigate the country’s No. 2 job.

This vice presidents' club, of sorts, is a sharp contrast to the bitter breakdown of communication between Trump and former President Barack Obama, as well as Trump’s notable distance from Obama's predecessor, George W. Bush, a fellow Republican.

Obama and Trump have not spoken or communicated privately in any way since the inauguration, nor have their wives, Michelle Obama and first lady Melania Trump, according to people familiar with the matter. NBC News interviewed more than a dozen people close to the current and former vice presidents for this story.

Obama and Bush, while wide apart on policy issues, were not in close contact during Obama’s first year in office but developed a warmer relationship over time. Bush and Trump have no relationship, and Bush is openly critical of Trump in an upcoming book, “The Last Republicans.” Laura Bush, however, has spoken at least once with Melania Trump since the inauguration, as she adjusts to life as first lady, a White House official said.

Biden and Cheney did not forge a relationship with each other like the one they have formed with Pence, and they had no contact in the months after the transition of power from Bush to Obama, said Ron Klain, Biden’s first chief of staff as vice president. Cheney was an outspoken critic of Obama at the time, specifically on foreign policy.

Pence’s discussions with his predecessors effectively position him as the highest profile link between Trump and the Republican and Democratic establishment figures he repeatedly rebukes. It also could put the vice president in a precarious position with his boss, who places a high value on loyalty and has been the target of criticism from Biden and Cheney.

“You’ve got to be loyal; you’ve got a constituent of one who is important,” said Joel Goldstein, a law professor at St. Louis University and an expert on the vice presidency.

Biden took aim at Trump this month, calling his foreign policy “beyond ideological incoherence” and his use of Twitter “childish.”

“It’s time to grow up,” Biden said at a Nov. 1 forum at the Chicago Council on Global Affairs.

An aide to Pence said the vice president doesn’t seek a signoff from Trump for his outside discussions, but given that the two speak daily, “I’m sure it wouldn’t come as a surprise to the president” that he talks with Biden and Cheney.

Vice President Joe Biden shakes hands with Vice President-elect Mike Pence after their meeting and lunch at the Naval Observatory in Washington on Nov. 16, 2016.Gary Cameron / Reuters file

The aide said Pence “shares a warm relationship” with Biden, “and they’ve spoken many times, particularly on foreign affairs matters.”

The outreach between Biden and Pence flows both ways.

Pence has called Biden before each of his foreign trips to get his views on the policies and personalities at play in the countries he was visiting. Biden, in turn, has spoken with Pence before his own overseas trips to inquire if the White House has any messages it would like him to deliver, or if there were any sensitivities around the administration’s policy efforts.

Biden also offers his advice based on his relationships with leaders Pence will encounter, and about the domestic political situations that might affect their thinking, people familiar with the discussions said.

“They talk on a fairly regular basis,” a person close to Biden said.

In June, for instance, Biden called Pence to check in on the status of Cyprus peace talks and discuss Greece’s economic stability ahead of a visit to Athens. Biden worked on both issues while in office.

The former vice president follows up with Pence after his meetings with world leaders to provide downloads of his talks, people familiar with the conversations said. It’s in those conversations, aides said, that Biden tries to diplomatically convey any concerns about Trump in particular that world leaders have raised.

But Biden’s willingness to offer counsel to his successor could carry some political risk if he still holds out the possibility of a White House run in 2020. If he entered the race, Biden would face Democrats in the primary who vehemently oppose the Trump administration.

Biden's aides said he’s expressed concerns about a breakdown of some norms and traditions under the Trump administration and wants to maintain an open line of communications. The conversations with Pence also keep Biden in the mix on policy issues he spent some four decades working on in Congress and the White House.

“He’s made it clear that any time Pence wants to give him a call, he’s available,” an aide to Biden said.

The camaraderie has even extended to their families, such as when Biden’s granddaughter spoke with Pence’s daughter about law schools.

Since January, Cheney has reached out to the vice president when he’s going to be in Washington to see if they can meet, a Pence aide said. Cheney visited the White House earlier this year where he spent time with Pence in his West Wing office. Another meeting they scheduled recently was canceled due to last-minute travel. More often Pence and Cheney speak on the phone, people close to Pence said.

“There aren’t very many of us,” Cheney noted about vice presidents when introducing Pence in February at an event for the Republican Jewish Coalition.

He described Pence as “somebody who’s got good experience and solid judgment and great background,” and stressed how increasingly significant vice presidents have become by taking on more responsibilities over the years.

When Trump named him as his running mate in the summer of 2016, Pence told ABC News he holds Cheney “in high regard.” Goldstein, the St. Louis University professor, said Cheney is someone Pence may see as a “wise elder statesperson” — even though Trump derides the GOP establishment — and their relationship suggests part of Pence’s portfolio is to serve as a bridge with that wing of the party.

Cheney has been publicly critical of Trump in the past, including during the campaign on his proposed ban on Muslims entering the U.S. “I think this whole notion that somehow we can just say no more Muslims, just ban a whole religion, goes against everything we stand for and believe in,” he told conservative talk radio host Hugh Hewitt in an interview during the campaign.

George W. Bush, according to “The Last Republicans,” did not vote for Trump. His father, George H.W. Bush, a former president and vice president, reportedly calls Trump a “blowhard” in the book. White House press secretary Sarah Huckabee Sanders fired back in a statement saying: “The American people voted to elect an outsider who is capable of implementing real, positive, and needed change — instead of a lifelong politician beholden to special interests. If they were interested in continuing decades of costly mistakes, another establishment politician more concerned with putting politics over people would have won.”

Biden, too, has been sharply critical of the administration’s foreign policy approach. But he still maintains his successor’s ear. Biden has privately encouraged Pence to take ownership of some of the foreign policy issues he oversaw, such as Latin America and Ukraine, people close to Biden said. He wrote a series of detailed, single spaced memos to Pence about those foreign policy challenges, aides said.

It’s the kind of advice Biden may not have entertained from his predecessor after taking office.

“He certainly wasn’t seeking advice from Dick Cheney about what to do in Iraq,” Klain said.

Pence’s foreign trips this year have included stops in Latin America and Eastern Europe. He’s scheduled to visit Israel and Egypt in December, which could prompt another round of advice from his predecessors.